COMMENT: Line 1 has to do with meaning or importance (gauravam), because of concern for which Nanda was stuck on his guru, the Buddha.

Line 2 has to do with sensual attachment, because of which Nanda was stuck on his wife, Sundari.

Line 3 has to do with action, in which area Nanda was unable to be decisive, because of being stuck in the horns of a meaning vs matter dilemma.

Line 4 paints a vivid picture of a real situation in nature.

In short, the point is that Nanda is stuck. And it is against this background that in 13.53 the Buddha will tell Nanda:

Thus, an object is not the cause

Of bondage or of liberation;

It is through a particular kind of fixing

That sticking occurs or does not.

EH Johnston:Reverence for the Buddha drew him forward, love for his wife drew him back again ; from irresolution he neither went away nor stood still, like a royal goose pressing forwards on the waves.

Linda Covill:Reverence for the Buddha drew him on, love for his wife drew him back again. He hesitated, neither going nor staying, like a king-goose pushing forwards against the waves.